The present invention generally relates to telephone network functionality, and more particularly, to a system and method for implementing class 5 end office switch functionality with extensions to interface with enhanced services such as voice response circuits, subscriber databases, and carrier databases. The system and method of the present invention are particularly suited for implementation between the physical circuit capabilities (signaling, Dual Tone Multi-Frequency (DTMF), call progress tone generation, and detection) and the transit networks within a telephone network.
High capacity end office switches, such as the Lucent 5ESS or the Nortel DMS-100/250, have very complex call models which are implemented in software consisting of millions of lines of code. These switching interfaces are designed to comply with standards set by Telcordia Technologies and the International Telecommunication Union (ITU). Telcordia Technologies (formerly Bellcore i.e., Bell Communications Research) is an industry consortium responsible for specifying telecommunications technology generic requirements for North America. The ITU (formerly CCITT i.e. Consultative Committee on International Telegraphy and Telephony) is a United Nations Agency within which governments and the private sector coordinate global telecom networks and services standards recommendations. Compliance with these standards guarantees that most of the standard telephone features will interoperate correctly in mixed manufacturer networks. The sheer size of the complex high-availability software applications that must conform to industry standards requirements makes adding new feature functionality difficult in these products.
Many of the standard Intelligent Network (IN) features (e.g., Automatic Recall (*69), Automatic Callback (*66 i.e., Bellcore TR-NWT-000227), (*66 i.e., Bellcore TR-NWT-0002215), Conditional Call Forwarding (*40, *42, *72 i.e., Bellcore TR-TSY-000580 and TR-TSY-000586); etc.) use digit sequences which are sometimes difficult to remember and have limited feedback mechanisms to indicate an error condition or guide inexperienced users. Because of this poor, yet simple human interface, some of the sophisticated features are not fully utilized. For example, features that require the user to program conditionals and number lists such as conditional call forwarding, speed dial, and selective call rejection are seldom used to their full potential. The introduction of new readily available technologies such as text to speech, voice processing, voice recognition, and the world-wide-web would be difficult to integrate without standards for interoperability.
Adding new features requires extensive development and testing initiatives due to the complexities of individual features and the large number of feature interactions that occur between different features. In addition, interacting with callers using voice recognition, or voice response circuits is not possible unless adjunct processing is utilized, since the vast install base of end office switches were not designed to perform these tasks.
Changes in dialing related features, such as equal access carrier selection, often requires software development and modifications by the switch manufacturer (e.g. Lucent, Nortel, etc.). In order to have true intelligence, many of the features require xe2x80x9cnetwork support.xe2x80x9d xe2x80x9cNetwork support,xe2x80x9d generally implies that messaging between end office switches is required to properly implement the feature. xe2x80x9cNetwork supportxe2x80x9d requires agreed upon interoperability standards to make features work. This often delays new feature introduction at central office locations that contain a mix of vendor products.
IN solutions based on xe2x80x9cevent triggersxe2x80x9d managed by service control point (SCP) network elements, require standards based network deployments. These solutions provide distributed features controlled from centrally located SMPs. A SCP is often implemented by a subscribing customer database. To date, very simple applications and call flows have been developed based on the IN architecture.
Due to deregulation, wide spread availability, and improvements in technology, many non-traditional solutions are being considered for local telephone use, including cable telephone, and wireless services. It is highly desirable for each non-traditional implementation of local telephone service to include all standard phone system functionality, as well as, enhanced services such as voice recognition, voice processing, and text to speech translation.
In an attempt to satisfy modern customer demands and requirements, administrators of today""s switching systems have attempted to integrate different types of computer hardware and operating systems into the central offices. Until now, this mixed environment of computer hardware and operating systems has prevented the distribution of new software applications, which would provide new enhanced features to customers and take full advantage of existing equipment capabilities.
In order to overcome some of the shortcomings of the traditional standards based network, and to achieve the objects and advantages of the present invention, the invention utilizes a programmable network Edge Switching Point (ESP), a Service Control Point (SCP), and a Service Management Point (SMP). The invention is a system and method for delivering class 5 office functionality with enhanced services such as embedded voice response and voice recognition utilizing a distributed self-contained logic system inserted between the physical circuit capabilities (signaling, tone generation, tone detection), and the transit networks. New sophisticated subscriber features can be activated simply by distributing call-processing logic to edge switching points. Although similar in capabilities to the IN architecture, this logic system is completely self-contained and does not require xe2x80x9cnetwork support.xe2x80x9d The logic is managed by an SMP. The SMP distributes and manages different versions of the logic as desired by the administrator of the system. The inputs to the logic system are signaling events and subscriber data. The outputs are call establishment requests, tone generation primitives, and tone detection primitives. The signaling inputs include traditional analog loopstart signals such as off-hook, flash-hook, on-hook, as well as GR-303 messages like SETUP, CALL PROCEEDING, ALERTING, CONNECT, CONNECT ACKNOWLEDGE, DISCONNECT, RELEASE, and RELEASE COMPLETE. Call establishment requests include all of the necessary signaling data to establish a network call using any of the following ISUP call setup message parameter elements: Automatic Number Identification (ANI), Dialed Number Identification Service (DNIS), Redirect, Presentation Indicator, Progress Indicator, Automatic Number Identification Information Integers (ANI-II i.e., type of station), and Carrier Identification Code (CIC).
The logic system was developed using a machine independent software language capable of being installed or updated from a central location. In addition, the language must be of the type that can be parsed and compiled to make subsequent execution efficient, as call processing is a real time application. Software programming and scripting languages that meet these requirements include Java, Java Script, Practical Extraction and Reporting Language, otherwise known as Pathologically Eclectic Rubbish Lister or PERL, and Python. All of these languages have mathematical and string processing capabilities as well as structured programming controls. Each of the above languages is either compiled or interpreted into universal operation code that is operating system and machine independent. Should the logic require dynamic modification, and/or request that a remote feature execute locally, the new logic can be retrieved, parsed, and executed as required. The logic can be distributed via Transmission Control Protocol/Internet Protocol (TCP/IP) as either an American Standard Code for Information Interchange (ASCII) text script file or machine independent compiled applets from a SMP to various SCPs and ESPs. It is important to note that the distributed logic of the present invention is not limited to the software languages previously recited.
It is an objective of this invention to implement a class 5 switch by receiving and processing edge switch events and sending switching primitive commands in order to setup and tear down calls on a routing network. The logic system which embodies the class 5 switch may be dynamically loaded, and may include innovative extensions to interface and operate with voice response circuits, SCPs, and traditional database architectures. These extensions provide new features and enhanced user interfaces for existing features.
New sophisticated features will be available by distributing the logic to switching end-points. The solution also scales because the high number of trigger interaction points are managed by the distributed logic, instead of round trip communications to a SCP, as defined in the IN architecture.
The system and method of the present invention allows for many different types or instances of complete call processing logic simultaneously, allowing different behavior for different user groups and individual users. The logic was further designed so that it may invoke another instance of the logic to permit feature behavior changes in real time for individual users as required.
Another advantage inherent in the present invention is the ability to deploy new or changed features easily and rapidly. The system and method of the present invention provides centralized distribution of logic to process events with real time updating at multiple remote locations. The system further provides a generalized database access mechanism with large scalability, as well as, a logic system which uses high level programming concepts, such as, control structures, scalar arithmetic, operators, regular expression string manipulation and pattern matching, and structured object-oriented constructs.
Another advantage of the present invention is that the system provides an xe2x80x9cinterceptxe2x80x9d trigger and line interaction layer between network interfaces and class 4 switching software. The system further provides a user modifiable state table for feature development.
Another significant advantage of the present invention is that it provides a complete set of user interface controls for use at the intercept logic system layer, including Dual Tone Multi-Frequency (DTMF) detection, Frequency Shift Keying (FSK) data bursts (from other FSK generating equipment and to the telephone subscriber""s equipment e.g., caller ID display unit), tone generation, voice prompting, voice recording, and speech recognition.